TWELVE people have been arrested in connection with the London terror attack which left seven people dead and 48 injured.

The arrests in Barking, east London, followed a raid at a flat belonging to one of the three attackers.

The arrests came as Assistant Commissioner Mark Rowley, the country’s head of counter-terrorism, said that eight police officers fired an “unprecedented” 50 bullets to kill the three London Bridge terrorists because they believed the attackers were wearing suicide belts.

Rowley also said a member of the public received a gunshot wound in the hail of bullets and that they remain in hospital in a non-critical condition.

Yesterday evening Canadian prime minister Justin Trudeau confirmed a Canadian was one of the seven killed. French foreign minister Jean-Yves Le Drian confirmed a French man was also one of the fatalities.

Last night, 36 people were being treated in hospital for various injuries, a number of them “extremely serious”, Rowley said.

“Eight police firearms officers discharged their weapons. Whilst this will be subject to an investigation by the IPCC, our initial assessment is in the region of 50 rounds – in the region of 50 bullets – were fired by those eight officers.

“The situation these officers were confronted with was critical – a matter of life and death – three armed men wearing what appeared to be suicide belts.”

Rowley added: “As the officers confronted a terrorist, a member of the public also suffered a gunshot wound. Although the injuries are not critical in nature, they are in hospital receiving medical attention.”

Giving an update on the investigation outside New Scotland Yard, he said “significant progress” had been made in identifying the attackers.

Rowley’s statement came as First Minister Nicola Sturgeon said Scotland would see a “substantial” increase in the number of armed police on duty in the immediate aftermath. But she said there was no intelligence of any specific threat to Scotland.

Sturgeon said: “As was the case after the Manchester attack, the public can expect to see a more visible police presence, particularly in busy areas. That will include armed police – the number of Armed Response Vehicles on duty today has been substantially increased.”

Speaking after chairing a meeting of the government’s emergency Cobra committee, Prime Minister Theresa May confirmed that campaigning for the General Election will resume today, after being suspended by all parties except Ukip.

The terror threat was not raised from its “severe” level at the Cobra meeting in response to Saturday night’s atrocity.

But May said she intended to take action on a range of levels in response to the recent spate of atrocities in the UK. She signalled action to clamp down on hate preaching and the use of the internet to spread Islamist ideology, as well as measures to end tolerance of extremism and a review of the powers of police and security agencies.

Meanwhile, witnesses described hearing shots as police arrested several people in connection with the attack. Residents said armed officers swooped on flats in Barking, where they believe one of the attackers may have lived.

Veronica Oladapo, 45, who lives in a neighbouring block, left her building at around 7am to see police taking four men and a woman away. She said: “When I came out they were already taking some of the casualties away. There were three of them ... the ambulance came and took them away. There were another two sitting down inside.”

Another neighbour said one of the attackers had asked him where he could hire a van.

Ken Chigbo said the man quizzed him on Saturday about the van he was using to move house. Chigbo said: “He was usually a really nice, friendly guy but this time it was on a different level of nice.

“He said to me: ‘Oh, where did you get your van, Ken? How much is it, is it possible to get in automatic?’– all these specific questions about the van, which obviously now makes sense in my head.”